ABSTRACT
Purpose: SARS-CoV-2 has caused an on-going global pandemic of COVID-19 disease. Vitamin-D has an immunomodulatory effect on the disease by suppressing the adaptive immune system which can lead to a cytokine storm, and boosting the innate immune system. This study evaluated the relationship between both the clinical characteristics of COVID-19 patients and the severity of their infections, and their serum Vitamin D levels. Material and methods: Forty COVID-19 patients from the period April to July, 2020, and 46 healthy subjects from a similar period in 2019, were included. Serum Vitamin-D level, clinical findings, comorbidities, chest computed tomography findings, hematological and serum biochemistry analyzes of the patients were evaluated. Results: COVID-19 patients had a significantly lower mean serum 25(OH) Vitamin-D level (12.86±6.27 ng/ mL) than healthy subjects (25.4±12.7 ng/mL) (p<0.001). The prevalence of Vitamin D deficiency in COVID-19 patients was high, not only in the elderly, but also in middle age and young patients. Ground-glass opacification and paving stone sign were the most frequent patterns observed in chest-computed tomography (CT) images. There was a significant negative relationship between Vitamin-D deficiency and C-reactive protein (CRP) level (p=0.0243). In addition, a high CRP level was associated with abnormal CT findings (p=0.001). Conclusion: The authors conclude that determining the Vitamin-D level in COVID-19 patients and administering it at the appropriate dosage can reduce the severity and progression of COVID-19 disease by contributing to the regulation of the cytokine storm and pulmonary inflammatory response. © 2022, Pamukkale University. All rights reserved.